In the past, avionics engineers have frequently included individual mistrim indicator dials for the pitch, roll and yaw axes. These indicator dials are typically connected via wires to the elevator, aileron, and rudder servos, respectively. While these indicator dials have gained widespread acceptance in the past, they have several serious drawbacks. First of all, the individual indicator dials require a pilot to look at several individual dials in order to assess the entire trim condition of the aircraft. Secondly, the dial information is displayed in such a way as to create confusion as to whether it indicates the present trim status of the aircraft or commands that the pilot should follow to correct a mistrim condition. Furthermore, the individual dials, with their individual connections to the servo motors, create potential for dangerous electromagnetic interference which might adversely effect the operation of the servo and consequently, the orientation of the critical control services of the aircraft.
Consequently, there exists a need for improvement in automatic flight control systems which provide for quick and easy assessment of mistrim conditions and needed corrective actions and also provide for enhanced reliability.